High-Current Cable Connector Locking for Low-Resistance Assembly

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Solution Overview

Problem

Existing cable connectors in the automotive sector face challenges with high current transmission, as plug connectors experience increased contact resistance and heat generation due to their design, leading to potential overheating and safety issues, while screw connectors are cumbersome and prone to assembly errors, making them unsuitable for automated production.

Innovation Solution

A cable connector design featuring two metal parts with large surface areas for efficient electrical and thermal conductivity, using materials like copper or aluminum alloys, with a locking mechanism that ensures secure contact without the complexity of screwing, allowing for quick and automated assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If spring-loaded plug connectors are used, then assembly is simple and fast, but contact resistance increases and Joule heating occurs due to limited contact area

Engineering Contradiction:
Improveassembly speedVSAvoidcontact resistance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent transitions from point-like contact (0D) to surface contact (2D) by designing contact surfaces with large area on the metal parts. This dimensional change allows for significantly reduced contact resistance while maintaining the simplicity of plug-in assembly, as the large surface area enables effective electrical contact without requiring multiple contact points or complex spring mechanisms

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Extent of automation

If spring-loaded plug connectors are used, then assembly is automated-friendly, but thermal mass is low leading to rapid heating and fire risk

Engineering Contradiction:
Improveautomated assembly capabilityVSAvoidthermal mass
Core Design Contradiction:
Extent of automationVSTemperature

Solution Approach 1:

The patent employs metal parts with inherently high thermal mass and thermal conductivity (such as aluminum or copper alloys) to replace the thin spring components. This material selection provides both the automation-friendly plug-in assembly and the necessary thermal capacity to absorb heat energy during high-current events, preventing rapid temperature rise and fire hazards

Inventive Principle:
Principle #40Composite materials

3Reliability

If screw connectors are used, then thermal conductivity and electrical conductivity improve due to large contact area, but assembly complexity increases and error susceptibility rises

Engineering Contradiction:
Improvethermal conductivityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent maintains the large surface area contact (2D) characteristic of screw connectors for optimal thermal and electrical conductivity, but eliminates the threading mechanism. The locking element provides sufficient normal force to press the large contact surfaces together, achieving the same conductivity benefits as screw connectors without the rotational assembly step, thereby reducing complexity and error susceptibility while maintaining high reliability

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The connector provides low ohmic resistance, effective heat dissipation, and rapid assembly, reducing the risk of overheating and assembly errors, making it suitable for high-current applications in electric vehicles.

Implementation Method 1

A locking element is provided which presses the first and second metal parts against one another using elastic deformation

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The electrical current flows between the spring and the base body at the contact points

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

Cables are therefore often an essential part of thermal management in vehicles

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4211755B1Cable connector for motor vehicles
Publication Date: 2024.04.17 AUTO KABEL MANAGEMENT GMBH
  • EP4211755B1 patent drawingFigure 1a~1b
  • EP4211755B1 patent drawingFigure 2~3a
  • EP4211755B1 patent drawingFigure 3b~3d

AI summary

The invention relates to a high-current cable connector (1) comprising two metal parts (20, 40) and a locking element (60). The metal parts (20, 40) are moved outward by means of the locking element (60) such that two abutment surfaces (22, 28, 42, 48) per metal part (20, 30) are pressed against each other. The orientation of the abutment surfaces (22, 28, 42, 48) has the result that two additional surfaces per metal part, the contact surfaces (24, 26, 44, 46), are likewise pressed against each other and the cable connector (1) is locked. This results in an easy-to-mount cable connector having low contact resistance and having high heat capacity.